NAME
Date::Manip - Date manipulation routines
SYNOPSIS
Date::Manip is a series of modules which can do pretty much any
date/time operation you could ever want.
As of 6.00, there are two ways to use Date::Manip.
Functional
Prior to 6.00, Date::Manip had only a functional interface. Existing
scripts which used older versions of Date::Manip will continue to
work (though you should check out the Date::Manip::Migration5to6
document for a list of changes which may be necessary).
Object-Oriented
As of 6.00, Date::Manip consists of a set of OO modules. Each have
their own document (see the SEE ALSO section below). The functional
interface is now just a wrapper around these OO modules.
The OO interface consists of the following modules:
Date::Manip::Date, Date::Manip::Delta, Date::Manip::Recur,
Date::Manip::TZ, and Date::Manip::Base
All Date::Manip operations can be performed using the OO modules.
Most of the common operations can also be done using the functional
interface, but there are some limitations.
The biggest limitation is that the functional interface has limited
time zone handling (though what it has is now correct). For full
time zone handling, you need to use the OO modules.
Which interface should you use?
If you need full time zone support, you need to use the OO interface
since the functional interface is limited in it's ability to handle time
zones correctly.
If you want to write a script that will work with older versions of
Date::Manip, you need to use the functional interface (but be aware that
not all config variables in 6.00 are available in 5.xx).
For new scripts, it is suggested that the OO interface be used.
FUNCTIONAL INTERFACE SYNOPSIS
use Date::Manip;
$version = DateManipVersion($flag);
Date_Init("VAR=VAL","VAR=VAL",...);
$date = ParseDate(\@args);
$date = ParseDate($string);
$date = ParseDate(\$string);
$date = ParseDateString($string);
@date = UnixDate($date,@format);
$date = UnixDate($date,@format);
$delta = ParseDateDelta(\@args);
$delta = ParseDateDelta($string);
$delta = ParseDateDelta(\$string);
@str = Delta_Format($delta,$dec,@format);
$str = Delta_Format($delta,$dec,@format);
$recur = ParseRecur($string,$base,$date0,$date1,$flags);
@dates = ParseRecur($string,$base,$date0,$date1,$flags);
$flag = Date_Cmp($date1,$date2);
$d = DateCalc($d1,$d2 [,$errref] [,$mode]);
$date = Date_SetTime($date,$hr,$min,$sec);
$date = Date_SetTime($date,$time);
$date = Date_SetDateField($date,$field,$val [,$nocheck]);
$date = Date_GetPrev($date,$dow,$today,$hr,$min,$sec);
$date = Date_GetPrev($date,$dow,$today,$time);
$date = Date_GetNext($date,$dow,$today,$hr,$min,$sec);
$date = Date_GetNext($date,$dow,$today,$time);
$name = Date_IsHoliday($date);
$listref = Events_List($date);
$listref = Events_List($date0,$date1);
$date = Date_ConvTZ($date,$from,$to);
$flag = Date_IsWorkDay($date [,$flag]);
$date = Date_NextWorkDay($date,$off [,$time]);
$date = Date_PrevWorkDay($date,$off [,$time]);
$date = Date_NearestWorkDay($date [,$tomorrowfirst]);
In the following routines, $y may be entered as either a 2 or 4 digit
year (it will be converted to a 4 digit year based on the variable
YYtoYYYY described below). Month and day should be numeric in all cases.
$day = Date_DayOfWeek($m,$d,$y);
$secs = Date_SecsSince1970($m,$d,$y,$h,$mn,$s);
$secs = Date_SecsSince1970GMT($m,$d,$y,$h,$mn,$s);
$days = Date_DaysSince1BC($m,$d,$y);
$day = Date_DayOfYear($m,$d,$y);
($y,$m,$d,$h,$mn,$s) = Date_NthDayOfYear($y,$n);
$days = Date_DaysInYear($y);
$days = Date_DaysInMonth($m,$y);
$wkno = Date_WeekOfYear($m,$d,$y,$first);
$flag = Date_LeapYear($y);
$day = Date_DaySuffix($d);
$tz = Date_TimeZone();
DESCRIPTION
Date::Manip is a series of modules designed to make any common date/time
manipulation easy to do. Operations such as comparing two times,
calculating a time a given amount of time from another, or parsing
international times are all easily done. From the very beginning, the
main focus of Date::Manip has been to be able to do ANY desired
date/time operation easily, not necessarily quickly. Also, it is
definitely oriented towards the type of operations we (as people) tend
to think of rather than those operations used routinely by computers.
There are other modules that can do a subset of the operations available
in Date::Manip much quicker than those presented here, so be sure to
read the section SHOULD I USE DATE::MANIP in the Date::Manip::Misc
document before deciding which of the Date and Time modules from CPAN is
for you.
Date::Manip deals with time as it is used in the Gregorian calendar (the
one currently in use) with full support for time changes due to daylight
saving time.
Date::Manip has functionality to work with several fundamental types of
data.
dates
A date consists of three pieces of information: a calendar date, a
time of day, and time zone information. All are fully handled.
delta
A delta is an amount of time (i.e. the amount of time between two
different dates).
recurrence
A recurring event is something which occurs on a regular recurring
basis.
Among other things, Date::Manip allow you to:
* Enter a date in practically any format you choose.
* Compare two dates, entered in widely different formats to determine
which is earlier.
* Extract any information you want from a date using a format string
similar to the Unix date command.
* Determine the amount of time between two dates, or add an amount of
time to a date to get a second date.
* Work with dates with dates using international formats (foreign
month names, 12/10/95 referring to October rather than December,
etc.).
* To find a list of dates where a recurring event happens.
Each of these tasks is trivial (one or two lines at most) with this
package.
ROUTINES
DateManipVersion
$version = DateManipVersion($flag);
Returns the version of Date::Manip. If $flag is non-zero, timezone
information is also returned.
Date_Init
Date_Init("VAR=VAL","VAR=VAL",...);
The Date_Init function is used to set any of the Date::Manip
configuration variables described in the Date::Manip::Config
document.
The strings to pass in are of the form "VAR=VAL". Any number may be
included and they can come in any order. VAR may be any
configuration variable. VAL is any allowed value for that variable.
For example, to switch from English to French and use non-US format
(so that 12/10 is Oct 12), do the following:
Date_Init("Language=French","DateFormat=non-US");
Note that variables are parsed in the order they are given, so
"DateFormat=non-US", "ConfigFile=./manip.cnf" may not give the
expected result. To be safe, ConfigFile should always appear first
in the list.
ParseDate
$date = ParseDate(\@args);
$date = ParseDate($string);
$date = ParseDate(\$string);
This takes an array or a string containing a date and parses it.
When the date is included as an array (for example, the arguments to
a program) the array should contain a valid date in the first one or
more elements (elements after a valid date are ignored). Elements
containing a valid date are shifted from the array. The largest
possible number of elements which can be correctly interpreted as a
valid date are always used. If a string is entered rather than an
array, that string is tested for a valid date. The string is
unmodified, even if passed in by reference.
The ParseDate routine is primarily used to handle command line
arguments. If you have a command where you want to enter a date as a
command line argument, you can use Date::Manip to make something
like the following work:
mycommand -date Dec 10 1997 -arg -arg2
No more reading man pages to find out what date format is required
in a man page.
Historical note: this is originally why the Date::Manip routines
were written (though long before they were released as the
Date::Manip module). I was using a bunch of programs (primarily
batch queue managers) where dates and times were entered as command
line options and I was getting highly annoyed at the many different
(but not compatible) ways that they had to be entered. Date::Manip
originally consisted of basically 1 routine which I could pass
"@ARGV" to and have it remove a date from the beginning.
ParseDateString
$date = ParseDateString($string);
This parses a string containing a date and returns it. Refer to the
Date::Manip::Date documentation for valid date formats. The date
returned is in the local time zone.
UnixDate
$out = UnixDate($date,$in);
@out = UnixDate($date,@in);
This takes a date and a list of strings containing formats roughly
identical to the format strings used by the UNIX date(1) command.
Each format is parsed and an array of strings corresponding to each
format is returned.
The formats are described in the Date::Manip::Date document.
ParseDateDelta
$delta = ParseDateDelta(\@args);
$delta = ParseDateDelta($string);
$delta = ParseDateDelta(\$string);
In the first form, it takes an array and shifts a valid delta from
it. In the other two forms, it parses a string to see if it contains
a valid delta.
A valid delta is returned if found. Otherwise, an empty string is
returned.
Delta_Format
$out = Delta_Format($delta [,$mode], $dec,$in);
@out = Delta_Format($delta [,$mode], $dec,@in);
This is similar to the UnixDate routine except that it extracts
information from a delta.
When formatting fields in a delta, the Date::Manip 6.00 formats have
changed and are much more powerful. The old 5.xx formats are still
available for the Delta_Format command for backward compatibility.
These formats include:
%Xv : print the value of the field X
%Xd : print the value of the field X and all
smaller units in terms of X
%Xh : print the value of field X and all
larger units in terms of X
%Xt : print the value of all fields in
terms of X
These make use of the $mode and $dec arguments to determine how to
format the information.
$dec is an integer, and is required, It tells the number of decimal
places to use.
$mode is either "exact" or "approx" and defaults to "exact" if it is
not included.
In "exact" mode, only exact relationships are used. This means that
there can be no mixing of the Y/M and W/D/H/MN/S segments (for
non-business deltas, or Y/M, W, and D/H/MN/S segments for business
deltas) because there is no exact relation between the fields of
each set.
In "approx" mode, approximate relationships are used. These are
described in the Date::Manip::Delta manual.
So, in "exact" mode, with a non-business delta, and $dec = 2, the
following are equivalent:
old style new style
--------- ---------
%Xv %Xv
%hd %.2hhs
%hh %.2hdh
%ht %.2hds
%yd %.2yyM
In "approximate" mode, the following are equivalent:
old style new style
--------- ---------
%Xv %Xv
%hd %.2hhs
%hh %.2hdh
%ht %.2hys
%yd %.2yys
If you want to use the new style formats in Delta_Format, use one of
the calls:
Delta_Format($delta, @in);
Delta_Format($delta, undef, @in);
If the first element of @in is an integer, you have to use the 2nd
form.
The old formats will remain available for the time being, though at
some point they may be deprecated.
DateCalc
$d = DateCalc($d1,$d2 [,\$err] [,$mode]);
This takes two dates, deltas, or one of each and performs the
appropriate calculation with them. Dates must be a string that can
be parsed by ParseDateString. Deltas must be a string that can be
parsed by ParseDateDelta. Two deltas add together to form a third
delta. A date and a delta returns a 2nd date. Two dates return a
delta (the difference between the two dates).
Since the two items can be interpreted as either dates or deltas,
and since many strings can be interpreted as both a date or a delta,
it is a good idea to pass the input through ParseDateDelta, if
appropriate if there is any ambiguity. For example, the string
"09:00:00" can be interpreted either as a date (today at 9:00:00) or
a delta (9 hours). To avoid unexpected results, avoid calling
DateCalc as:
$d = DateCalc("09:00:00",$someothervalue);
Instead, call it as:
$d = DateCalc(ParseDate("09:00:00"),$someothervalue);
to force it to be a date, or:
$d = DateCalc(ParseDateDelta("09:00:00"),$someothervalue);
to force it to be a delta. This will avoid unexpected results.
Passing something through ParseDate is optional since they will be
treated as dates by default (and for performance reasons, you're
better off not calling ParseDate).
If there is no ambiguity, you are better off NOT doing this for
performance reasons. If the delta is a business delta, you
definitely should NOT do this.
One other thing to note is that when parsing dates, a delta can be
interpreted as a date relative to now. DateCalc will ALWAYS treat a
delta as a delta, NOT a date.
For details on how calculations are done, refer to the
Date::Manip::Calc documentation.
By default, math is done using an exact mode.
If two deltas, or a date and a delta are passed in, $mode may be
used to force the delta to be either business or non-business mode
deltas. If $mode is 0 or 1, the delta(s) will be non-business.
Otherwise, they will be business deltas. If $mode is passed in, it
will be used only if the business or non-business state was not
explicitly set in the delta.
If two dates are passed in, $mode is used to determine the type of
calculation. By default, an exact delta is produced. If $mode is 1,
an approximate delta is produced. If $mode is 2, a business
approximate (bapprox) mode calculation is done. If $mode is 3, a
exact business mode delta is produced.
If \$err is passed in, it is set to: 1 is returned if $d1 is not a
delta or date 2 is returned if $d2 is not a delta or date 3 if any
other error occurs. This argument is optional, but if included, it
must come before $mode.
Nothing is returned if an error occurs.
ParseRecur
$recur = ParseRecur($string [,$base,$date0,$date1,$flags]);
@dates = ParseRecur($string [,$base,$date0,$date1,$flags]);
This parses a string containing a recurrence and returns a fully
specified recurrence, or a list of dates referred to.
$string can be any of the forms:
FREQ
FREQ*FLAGS
FREQ*FLAGS*BASE
FREQ*FLAGS*BASE*DATE0
FREQ*FLAGS*BASE*DATE0*DATE1
where FREQ is a frequence (see the Date::Manip::Delta
documentation), FLAGS is a comma separated list of flags, and BASE,
DATE0, and DATE1 are date strings. The dates and flags can also be
passed in as $base, $date0, $date1, and $flags, and these will
override any values in $string.
In scalar context, the fully specified recurrence (or as much
information as is available) will be returned. In list context, a
list of dates will be returned.
Date_Cmp
$flag = Date_Cmp($date1,$date2);
This takes two dates and compares them. Any dates that can be parsed
will be compared.
Date_GetPrev
$date = Date_GetPrev($date,$dow, $curr [,$hr,$min,$sec]);
$date = Date_GetPrev($date,$dow, $curr [,$time]);
$date = Date_GetPrev($date,undef,$curr,$hr,$min,$sec);
$date = Date_GetPrev($date,undef,$curr,$time);
This takes a date (any string that may be parsed by ParseDateString)
and finds the previous occurrence of either a day of the week, or a
certain time of day.
This is documented in the "prev" method in Date::Manip::Date, except
that here, $time is a string (HH, HH:MN:, or HH:MN:SS), and $dow may
be a string of the form "Fri" or "Friday".
Date_GetNext
$date = Date_GetNext($date,$dow, $curr [,$hr,$min,$sec]);
$date = Date_GetNext($date,$dow, $curr [,$time]);
$date = Date_GetNext($date,undef,$curr,$hr,$min,$sec);
$date = Date_GetNext($date,undef,$curr,$time);
Similar to Date_GetPrev.
Date_SetTime
$date = Date_SetTime($date,$hr,$min,$sec);
$date = Date_SetTime($date,$time);
This takes a date (any string that may be parsed by ParseDateString)
and sets the time in that date. For example, one way to get the time
for 7:30 tomorrow would be to use the lines:
$date = ParseDate("tomorrow");
$date = Date_SetTime($date,"7:30");
$time is a string (HH, HH:MN, or HH:MN:SS).
Date_SetDateField
$date = Date_SetDateField($date,$field,$val);
This takes a date and sets one of its fields to a new value. $field
is any of the strings "y", "m", "d", "h", "mn", "s" (case
insensitive) and $val is the new value.
Date_IsHoliday
$name = Date_IsHoliday($date);
This returns undef if $date is not a holiday, or a string containing
the name of the holiday otherwise. An empty string is returned for
an unnamed holiday.
Date_IsWorkDay
$flag = Date_IsWorkDay($date [,$flag]);
This returns 1 if $date is a work day. If $flag is non-zero, the
time is checked to see if it falls within work hours. It returns an
empty string if $date is not valid.
Events_List
$ref = Events_List($date);
$ref = Events_List($date,0 [,$flag]);
$ref = Events_List($date,$date1 [,$flag]);
This returns a list of events. If $flag is not given, or is equal to
0, the list (returned as a reference) is similar to the the list
returned by the Date::Manip::Date::list_events method with $format =
"dates". The only difference is that it is formatted slightly
different to be backward compatible with Date::Manip 5.xx.
The data from the list_events method is:
( [DATE1, NAME1a, NAME1b, ...],
[DATE2, NAME2a, NAME2b, ...],
...
)
The reference returned from Events_List (if $flag = 0) is:
[ DATE1, [NAME1a, NAME1b, ...],
DATE2, [DATE2a, DATE2b, ...],
...
]
For example, if the following events are defined:
2000-01-01 ; 2000-03-21 = Winter
2000-03-22 ; 2000-06-21 = Spring
2000-02-01 = Event1
2000-05-01 = Event2
2000-04-01-12:00:00 = Event3
the following examples illustrate the function:
Events_List("2000-04-01")
=> [ 2000040100:00:00, [ Spring ] ]
Events_List("2000-04-01 12:30");
=> [ 2000040112:30:00, [ Spring, Event3 ] ]
Events_List("2000-04-01",0);
=> [ 2000040100:00:00, [ Spring ],
2000040112:00:00, [ Spring, Event3 ],
2000040113:00:00, [ Spring ] ]
Events_List("2000-03-15","2000-04-10");
=> [ 2000031500:00:00, [ Winter ],
2000032200:00:00, [ Spring ]
2000040112:00:00, [ Spring, Event3 ]
2000040113:00:00, [ Spring ] ]
If $flag is 1, then a tally of the amount of time given to each
event is returned. Time for which two or more events apply is
counted for both.
Events_List("2000-03-15","2000-04-10",1);
=> { Event3 => +0:0:+0:0:1:0:0,
Spring => +0:0:+2:4:23:0:0,
Winter => +0:0:+1:0:0:0:0
}
When $flag is 2, a more complex tally with no event counted twice is
returned.
Events_List("2000-03-15","2000-04-10",2);
=> { Event3+Spring => +0:0:+0:0:1:0:0,
Spring => +0:0:+2:4:22:0:0,
Winter => +0:0:+1:0:0:0:0
}
The hash contains one element for each combination of events.
In both of these cases, there may be a hash element with an empty
string as the key which contains the amount of time with no events
active.
Date_DayOfWeek
$day = Date_DayOfWeek($m,$d,$y);
Returns the day of the week (1 for Monday, 7 for Sunday).
Date_SecsSince1970
$secs = Date_SecsSince1970($m,$d,$y,$h,$mn,$s);
Returns the number of seconds since Jan 1, 1970 00:00 (negative if
date is earlier).
Date_SecsSince1970GMT
$secs = Date_SecsSince1970GMT($m,$d,$y,$h,$mn,$s);
Returns the number of seconds since Jan 1, 1970 00:00 GMT (negative
if date is earlier).
Date_DaysSince1BC
$days = Date_DaysSince1BC($m,$d,$y);
Returns the number of days since Dec 31, 1BC. This includes the year
0001.
Date_DayOfYear
$day = Date_DayOfYear($m,$d,$y);
Returns the day of the year (1 to 366)
Date_NthDayOfYear
($y,$m,$d,$h,$mn,$s) = Date_NthDayOfYear($y,$n);
Returns the year, month, day, hour, minutes, and decimal seconds
given a floating point day of the year.
All arguments must be numeric. $n must be greater than or equal to 1
and less than 366 on non-leap years and 367 on leap years.
NOTE: When $n is a decimal number, the results are non-intuitive
perhaps. Day 1 is Jan 01 00:00. Day 2 is Jan 02 00:00. Intuitively,
you might think of day 1.5 as being 1.5 days after Jan 01 00:00, but
this would mean that Day 1.5 was Jan 02 12:00 (which is later than
Day 2). The best way to think of this function is a time line
starting at 1 and ending at 366 (in a non-leap year). In terms of a
delta, think of $n as the number of days after Dec 31 00:00 of the
previous year.
Date_DaysInYear
$days = Date_DaysInYear($y);
Returns the number of days in the year (365 or 366)
Date_DaysInMonth
$days = Date_DaysInMonth($m,$y);
Returns the number of days in the month.
Date_WeekOfYear
$wkno = Date_WeekOfYear($m,$d,$y,$first);
Figure out week number. $first is the first day of the week which is
usually 1 (Monday) or 7 (Sunday), but could be any number between 1
and 7 in practice.
NOTE: This routine should only be called in rare cases. Use UnixDate
with the %W, %U, %J, %L formats instead. This routine returns a week
between 0 and 53 which must then be "fixed" to get into the ISO-8601
weeks from 1 to 53. A date which returns a week of 0 actually
belongs to the last week of the previous year. A date which returns
a week of 53 may belong to the first week of the next year.
Date_LeapYear
$flag = Date_LeapYear($y);
Returns 1 if the argument is a leap year Written by David Muir
Sharnoff
Date_DaySuffix
$day = Date_DaySuffix($d);
Add `st', `nd', `rd', `th' to a date (i.e. 1st, 22nd, 29th). Works
for international dates.
Date_TimeZone
$tz = Date_TimeZone;
This determines and returns the local time zone. If it is unable to
determine the local time zone, the following error occurs:
ERROR: Date::Manip unable to determine Time Zone.
See the Date::Manip::TZ documentation (DETERMINING THE LOCAL TIME
ZONE) for more information.
Date_ConvTZ
$date = Date_ConvTZ($date,$from,$to);
This converts a date (which MUST be in the format returned by
ParseDate) from one time zone to another.
$from and $to each default to the local time zone. If they are
given, they must be any time zone or alias understood by
Date::Manip.
If an error occurs, an empty string is returned.
Date_NextWorkDay
$date = Date_NextWorkDay($date,$off [,$time]);
Finds the day $off work days from now. If $time is passed in, we
must also take into account the time of day.
If $time is not passed in, day 0 is today (if today is a workday) or
the next work day if it isn't. In any case, the time of day is
unaffected.
If $time is passed in, day 0 is now (if now is part of a workday) or
the start of the very next work day.
Date_PrevWorkDay
$date = Date_PrevWorkDay($date,$off [,$time]);
Similar to Date_NextWorkDay.
Date_NearestWorkDay
$date = Date_NearestWorkDay($date [,$tomorrowfirst]);
This looks for the work day nearest to $date. If $date is a work
day, it is returned. Otherwise, it will look forward or backwards in
time 1 day at a time until a work day is found. If $tomorrowfirst is
non-zero (or if it is omitted and the config variable TomorrowFirst
is non-zero), we look to the future first. Otherwise, we look in the
past first. In other words, in a normal week, if $date is Wednesday,
$date is returned. If $date is Saturday, Friday is returned. If
$date is Sunday, Monday is returned. If Wednesday is a holiday,
Thursday is returned if $tomorrowfirst is non-nil or Tuesday
otherwise.
For all of the functions which return a date, the format of the returned
date is governed by the Printable config variable. If a date is
returned, it is in the local time zone, NOT the time zone the date was
parsed in.
SEE ALSO
The following documents describe various parts of Date::Manip. The
following documents describe the basic operation of the Date::Manip
package:
An introduction to the Date::Manip classes and how to configure them:
Date::Manip::Objects - a basic description of the various
Date::Manip modules, and how they
work together, and how configuration
affects them
Date::Manip::Config - information for configuring
Date::Manip
The methods available in each class:
Date::Manip::Obj - base class (modules listed below
inherit the methods defined in this
class)
Date::Manip::Base - module for doing low-level date
operations
Date::Manip::TZ - module for working with time zones
Date::Manip::Date - date operations
Date::Manip::Delta - delta operations
Date::Manip::Recur - recurrence operations
Miscellaneous information:
Date::Manip::Zones - time zone data included in Date::Manip
Date::Manip::Calc - date calculations
Date::Manip::Holidays - information on defining and using
holidays and events
Information about the module and administrative things:
Date::Manip::Migration5to6
- information on changes necessary
to scripts when upgrading from
5.xx to 6.xx
Date::Manip::Misc - miscellaneous information about
Date::Manip (who should use it;
acknowledgements)
Date::Manip::Changes5 - backward incompatible changes in
Date::Manip 5.xx
Date::Manip::Changes5to6- differences between version 5.xx
and 6.00 (including information
on upgrading)
Date::Manip::Changes6 - backward incompatible changes in
Date::Manip 6.xx
Date::Manip::Problems - common problems and instructions
for reporting bugs
Date::Manip::Examples - examples of how to use Date::Manip
LICENSE
This script is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
AUTHOR
Sullivan Beck (sbeck@cpan.org)